Communication management system, communication system, computer-readable recording medium, and maintenance system

ABSTRACT

A communication management system includes: a storage unit configured to store destination information of a first communication terminal that establishes a first session with a relay device that relays communication data, destination information of a conversion system that performs mutual conversion between communication schemes of communication data transmitted from the first communication terminal and a second communication terminal and establishes a second session with the relay device, and destination information of the second communication terminal that establishes a third session with the conversion system; a receiving unit configured to receive start request information to start communication between the communication terminals from the first communication terminal; an extracting unit configured to extract destination information of each communication terminal and the conversion system stored in the storage unit, based on the received start request information; and a transmitting unit configured to transmit the extracted destination information to the relay device.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims the benefit ofpriority under 35 U.S.C. § 120 from U.S. application Ser. No. 15/868,598filed Jan. 11, 2018, which is a continuation of U.S. application Ser.No. 15/133,905 filed Apr. 20, 2016 (now U.S. Pat. No. 9,912,906 issuedMar. 6, 2018), which is a continuation of U.S. application Ser. No.14/368,986 filed Jun. 26, 2014 (now U.S. Pat. No. 9,350,947 issued May24, 2016), the entire contents of both of which are incorporated hereinby reference. U.S. application Ser. No. 14/368,986 is a national stageof International Application No. PCT/JP2012/084288 filed Dec. 26, 2012,and claims the benefit of priority under 35 U.S.C. § 119 from priorJapanese Patent Applications No. 2011-285768 filed Dec. 27, 2011 and No.2012-262456 filed Nov. 30, 2012.

TECHNICAL FIELD

The present invention relates to management of first and secondcommunication terminals that transmit and receive predetermined calldata.

BACKGROUND ART

In recent years, with the request for reduction of business tripexpenses and a business trip time, call systems in which videoconferences are performed through a communication network such as theInternet are in widespread use. In this call system, a video conferencecan be conducted such that image data and audio data are transmitted andreceived between a plurality of call terminals.

Besides a call system of a type in which image data and audio data aretransmitted and received directly between call terminals, videoconference systems of a type in which a plurality of relay devices areused to relay image data and audio data between a plurality of callterminals have been emerged (see Japanese Patent Application Laid-openNo. 2008-227577).

However, in the video conference call system according to the relatedart, it is difficult to implement a call between call terminals usingdifferent call schemes. In other words, when call terminals differ incall scheme from each other, for example, when call terminals differ inat least one of a call control scheme (a call control protocol) forestablishing or disconnecting a connection with a destination of a calland a coding scheme for converting image data and audio data into IPpackets, there occurs a problem in that it is difficult to implement acall between the call terminals.

DISCLOSURE OF INVENTION

It is an object of the present invention to at least partially solve theproblems in the conventional technology.

According to an embodiment, a communication management system formanaging first and second communication terminals that transmit andreceive predetermined communication data. The communication managementsystem includes a storage unit configured to store therein destinationinformation representing a destination of the first communicationterminal that establishes a first communication session with a relaydevice that relays the communication data, destination informationrepresenting a destination of a conversion system that performs mutualconversion between a communication scheme of communication datatransmitted from the first communication terminal and a communicationscheme of communication data transmitted from the second communicationterminal and establishes a second communication session with the relaydevice, and destination information representing a destination of thesecond communication terminal that establishes a third communicationsession with the conversion system; a receiving unit configured toreceive start request information to start communication between thefirst communication terminal and the second communication terminal fromthe first communication terminal; an extracting unit configured toextract destination information of each of the first and the secondcommunication terminals and the conversion system stored in the storageunit, on the basis of the received start request information; and atransmitting unit configured to transmit the extracted destinationinformation to the relay device.

The above and other objects, features, advantages and technical andindustrial significance of this invention will be better understood byreading the following detailed description of presently preferredembodiments of the invention, when considered in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a call system according to anembodiment;

FIG. 2 is a conceptual diagram illustrating a communication status whena call is implemented between call terminals having the samecommunication scheme;

FIG. 3 is a conceptual diagram illustrating image quality of image datatransmitted and received according to an SVC standard in FIGS. 2 and 4;

FIG. 4 is a conceptual diagram illustrating a communication status whena call is implemented between call terminals having differentcommunication schemes;

FIG. 5 is a conceptual diagram illustrating image quality of image datatransmitted and received according to an AVC standard in FIG. 4;

FIG. 6 is an external appearance diagram of a call terminal according tothe present embodiment;

FIG. 7 is a hardware configuration diagram of a call terminal accordingto the present embodiment;

FIG. 8 is a hardware configuration diagram of a call management system,a relay device, a conversion system, a program providing system, or amaintenance system according to the present embodiment;

FIG. 9 is a functional block diagram of a call terminal, a relay device,a call management system, and a conversion system that configure a partof a call system according to an embodiment;

FIG. 10 is a conceptual diagram illustrating a changed qualitymanagement table;

FIG. 11 is a conceptual diagram illustrating a relay device managementtable;

FIG. 12 is a conceptual diagram illustrating a terminal informationmanagement table;

FIG. 13 is a conceptual diagram illustrating a terminal statusmanagement table;

FIG. 14 is a conceptual diagram illustrating a destination listmanagement table;

FIG. 15 is a conceptual diagram illustrating a session management table;

FIG. 16 is a conceptual diagram illustrating a conversion managementtable;

FIG. 17 is a conceptual diagram illustrating a quality management table;

FIG. 18 is a sequence diagram illustrating a process of a preliminarystep to start a call between terminals;

FIG. 19 is a sequence diagram illustrating a call start request;

FIG. 20 is a flowchart illustrating a determination of a communicationscheme;

FIG. 21 is a sequence diagram illustrating a process of establishing acommunication session before a call is performed between two dedicatedterminals;

FIG. 22 is a sequence diagram illustrating a process of transmitting andreceiving call data between two dedicated terminals;

FIG. 23 is a sequence diagram illustrating a process of establishing acommunication session before a call is performed between a dedicatedterminal and a non-dedicated terminal;

FIG. 24 is a sequence diagram illustrating a process of transmitting andreceiving call data between a dedicated terminal and a non-dedicatedterminal; and

FIG. 25 is a conceptual diagram illustrating an image quality of imagedata converted by a conversion system.

BEST MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described withreference to FIGS. 1 to 25.

Overall Configuration of Embodiment

FIG. 1 is a schematic diagram of a call system according to anembodiment of the present invention.

Referring to FIG. 1, a call system 1 is constructed by a plurality ofcall terminals (10 aa, 10 ab, . . . ), displays (120 aa, 120 ab, . . . )of the respective call terminals (10 aa, 10 ab, . . . ), a plurality ofrelay devices (30 a, 30 b, and 30 c), a call management system 50, aconversion system 80, a program providing system 90, and a maintenancesystem 100. Through the call system 1, communication of image data andaudio data as an example of call data is performed, and thus, forexample, a video conference between remote sites can be implemented. Aplurality of routers (70 a, 70 b, 70 c, 70 d, 70 ab, and 70 cd) selectan optimal path of call data.

The call terminals (10 aa, 10 ab, 10 ac, . . . ), the relay device 30 a,and the router 70 a are connected to perform communication with oneanother via a local area network (LAN) 2 a. The call terminals (10 ba,10 bb, 10 bc, . . . ), the relay device 30 b, and the router 70 b areconnected to perform communication with one another via a LAN 2 b. TheLAN 2 a and the LAN 2 b are connected to perform communication with eachother via a dedicated line 2 ab including the router 70 ab. Further, theLAN 2 a, the LAN 2 b, and the dedicated line 2 ab are constructed in apredetermined region X. For example, the region X is Japan, the LAN 2 ais constructed in a business office in Tokyo, and the LAN 2 b isconstructed in a business office in Osaka.

Meanwhile, the call terminals (10 ca, 10 cb, 10 cc, . . . ), the relaydevice 30 c, and the router 70 c are connected to perform communicationwith one another via a LAN 2 c. The call terminals (10 da, 10 db, 10 dc,. . . ), the conversion system 80, and the router 70 d are connected toperform communication with one another via a LAN 2 d. Further, the LAN 2c and the LAN 2 d are connected to perform communication with each othervia a dedicated line 2 cd including the router 70 cd. Further, the LAN 2c, the LAN 2 d, and the dedicated line 2 cd are constructed in apredetermined region Y. For example, the region Y is the USA, the LAN 2c is constructed in a business office in New York, and the LAN 2 d isconstructed in a business office in Washington D.C. The region X and theregion Y are connected to perform communication with each other via theInternet 2 i from the routers (70 ab, 70 cd).

In the following, a “call terminal” is referred to simply as a“terminal”, and a “call management system” is referred to simply as a“management system”. An arbitrary one of a plurality of terminals (10aa, 10 ab, . . . ) is referred to as a “terminal 10”, an arbitrary oneof a plurality of displays (120 aa, 120 ab, . . . ) is referred to as a“display 120”, and an arbitrary one of a plurality of relay devices (30a, 30 b, 30 c) is referred to as a “relay device 30”. Further, aterminal serving as a request source that requests a start of a videoconference is referred to as a “request source terminal”, and a terminalserving as a destination (a relay destination) that is a requestdestination is referred to as a “destination terminal”. Further, anarbitrary one of the routers (70 a, 70 b, 70 c, 70 d, 70 ab, 70 cd) isreferred to as a “router 70”.

The call management system 50, the program providing system 90, and themaintenance system 100 are connected to the Internet 2 i. In the presentembodiment, the conversion system 80 is connected to the router 70 d inthe LAN 2 d in the region Y. The call management system 50, the programproviding system 90, and the maintenance system 100 may be installed inthe region X or the region Y or may be installed in any other region.

In the present embodiment, a communication network 2 of the presentembodiment is constructed by the LAN 2 a, the LAN 2 b, the dedicatedline 2 ab, the Internet 2 i, the dedicated line 2 cd, the LAN 2 c, andthe LAN 2 d. In the communication network 2, there may be a place inwhich communication is performed in a wireless manner such as WiFi(Wireless Fidelity) or Bluetooth (registered trademark) as well as awired manner.

In FIG. 1, 4-set digits illustrated below each terminal 10, each relaydevice 30, the call management system 50, each router 70, the conversionsystem 80, the program providing system 90, and the maintenance system100 simply represent an IP address in typical IPv4. For example, the IPaddress of the terminal 10 aa is “1.2.1.3”. IPv6 may be used rather thanIPv4, but the description will proceed with IPv4 for the sake ofsimplification of description.

Each terminal 10 may be used not only for a call between a plurality ofbusiness offices or a call between different rooms in the same businessoffice but also for a call within the same room, a call between anindoor place and an outdoor place, or a call between outdoor places.When each terminal 10 is used outdoor, communication is performed by awireless manner such as a cellular telecommunication network.

Each terminal 10 illustrated in FIG. 1 is a terminal that implements auser's call by transmitting and receiving call data, and is a terminalfor a video conference, for example. Further, the terminal 10 performstransmission and reception of call data using a predeterminedcommunication scheme (a call control scheme for establishing ordisconnecting a connection with a destination of a call and a codingscheme for converting call data into IP packets).

Here, the examples of the call control scheme includes (1) a sessioninitiation protocol (SIP), (2) a H.323, (3) a protocol extended from theSIP, (4) a protocol of an instant messenger, (5) a protocol using aMESSAGE method of the SIP, (6) a protocol of Internet Relay Chat (IRC),and (7) a protocol extended from a protocol of an instant messenger. Ofthese, for example, (4) the protocol of the instant messenger is aprotocol used for (4-1) an extensible messaging and presence protocol(XMPP) or (4-2) a protocol used in ICQ (registered trademark), AIM(registered trademark), Skype (registered trademark), or the like.Further, for example, (7) the protocol extended from the protocol of theinstant messenger is jingle.

Among a plurality of terminals 10, a terminal 10 that uses acommunication scheme in which a call control scheme is a protocol of aninstant messenger (or a protocol extended from a protocol of an instantmessenger), and a coding scheme is a scalable video coding (SVC) isreferred to as a “dedicated terminal A”. Further, among a plurality ofterminals 10, a terminal 10 that has an IP address that is not managedby the call management system 50 and uses a communication scheme inwhich at least one of the call control scheme and the coding scheme isdifferent from one of the dedicated terminal A is referred to as a“non-dedicated terminal D”. Further, in the present embodiment,“dedicated terminal A” is described as a terminal which is manufactured,sold, or managed by a specific company, and the “non-dedicated terminalD” is described as a terminal which is manufactured, sold, or managed bya company other than the specific company. In the present embodiment,since terminals which are manufactured, sold, or managed by differentcompanies are likely to differ in communication scheme from each other,the description will proceed with this example. In addition, as examplesof two terminals having different communication schemes, among terminalsmanufactured or sold by the same company, a terminal which is new in amanufacturing or selling time is referred to as a “dedicated terminalA”, and an old terminal is referred to as a “non-dedicated terminal D”.

Each relay device 30 is a computer system that relays call data betweenthe plurality of terminals 10. The call management system 50 is acomputer system that performs login authentication from the terminal 10,management of a call status of the terminal 10, management of adestination list, and management of a communication status of the relaydevice 30 in an integrated fashion. An image of image data may be eitheror both of a moving image and a still image.

The conversion system 80 undertakes a signaling gateway that performsconversion of a call control signal and a video/audio gateway thatperforms encoding of call data. In other words, the conversion system 80is a gateway that performs mutual conversion of a communication schemeof call data transmitted from a request source terminal and acommunication scheme (a call control scheme and a coding scheme) of calldata transmitted from a destination terminal, and converts at least oneof a call control scheme and a coding scheme.

The program providing system 90 is a computer system that providesprograms to be used to the terminal 10, the relay device 30, the callmanagement system 50, the conversion system 80, and the maintenancesystem 100 via the communication network 2, respectively.

The maintenance system 100 is a computer system that performsmaintenance, management, or repair of at least one of the terminal 10,the relay device 30, the call management system 50, the conversionsystem 80, and the program providing system 90. For example, when themaintenance system 100 is installed inside the country, and the terminal10, the relay device 30, the call management system 50, the conversionsystem 80, or the program providing system 90 is installed outside thecountry, the maintenance system 100 remotely performs maintenance, thatis, maintenance, management, or repair of at least one of the terminal10, the relay device 30, the call management system 50, the conversionsystem 80, and the program providing system 90 via the communicationnetwork 2. Further, the maintenance system 100 performs maintenance suchas management of a model number, a manufacturing number, a salesdestination, a repair check, or a failure history of at least one of theterminal 10, the relay device 30, the call management system 50, theconversion system 80, and the program providing system 90 without thecommunication network 2.

Next, a first communication pattern for implementing a call between twodedicated terminals A will be described with reference to FIGS. 2 and 3.FIG. 2 is a conceptual diagram illustrating a communication status whena call is implemented between call terminals having the samecommunication scheme.

Referring to FIG. 2, in the first communication pattern, the call system1 performs communication of call data using a video coding standard ofH.264/SVC. Specifically, in the call system 1, a managementcommunication session sei to transmit and receive various kinds ofmanagement information is established between a request source terminalof a dedicated terminal A and a destination terminal of a dedicatedterminal A through the call management system 50 as illustrated in FIG.2. Further, four communication sessions to transmit and receive fourpieces of data, that is, high-resolution image data, moderate-resolutionimage data, low-resolution image data, and audio data through the relaydevice 30 are established between the request source terminal and thedestination terminal.

In FIG. 2, four communication sessions established between the requestsource terminal and the relay device 30 are represented as a firstcommunication session sed1 for call data. Further, four communicationsessions established between the relay device 30 and the destinationterminal are represented as a second communication session sed2 for calldata.

Here, the resolution of an image of image data handled by the firstcommunication pattern illustrated in FIG. 2 will be described withreference to FIG. 3. FIG. 3 is a conceptual diagram illustrating animage quality of image data transmitted and received according to theSVC standard in FIG. 2.

There are a low-resolution image including 160×120 pixels as illustratedin (a) of FIG. 3 as a base image, a moderate-resolution image including320×240 pixels as illustrated in (b) of FIG. 3, and a high-resolutionimage including 640×480 pixels as illustrated in (c) of FIG. 3. Ofthese, in a narrow band route, low-quality image data includinglow-resolution image data as a base image is relayed by the relay device30. However, when a band is relatively broad, moderate-quality imagedata including low-resolution image data serving as a base image andmoderate-resolution image data is relayed by the relay device 30.Further, when a band is extremely broad, high-quality image dataincluding low-resolution image data serving as a base image,moderate-resolution image data, and high-resolution image data isrelayed by the relay device 30.

Next, a second communication pattern for implementing a call between adedicated terminal A and a non-dedicated terminal D will be describedwith reference to FIGS. 4 and 5. FIG. 4 is a conceptual diagramillustrating a communication status when a call is implemented betweencall terminals having different communication schemes.

Referring to FIG. 4, in the second communication pattern, the callsystem 1 performs communication of call data using a video codingstandard of H.264/SVC and a video coding standard of H.264/AVC (AdvancedVideo Coding). Specifically, in the call system 1, a managementcommunication session sei to transmit and receive various kinds ofmanagement information is established between a request source terminalof a dedicated terminal A and a destination terminal of a non-dedicatedterminal D through the call management system 50 as illustrated in FIG.4.

Further, four communication sessions to transmit and receive four piecesof data, that is, high-resolution image data, moderate-resolution imagedata, low-resolution image data, and audio data based on H.264/SVCthrough the relay device 30 are established between the request sourceterminal (an example of a first communication terminal) and theconversion system 80. In FIG. 4, four communication sessions establishedbetween the request source terminal and the relay device 30 arerepresented as a first communication session sed11 for call data.Further, four communication sessions established between the relaydevice 30 and the conversion system 80 are represented as a secondcommunication session sed12 for call data.

Further, two communication sessions to transmit and receive two piecesof data, that is, moderate-resolution image data and audio data based onH.264/AVC are established between the conversion system 80 and thedestination terminal (an example of a second communication terminal). InFIG. 4, two communication sessions established between the conversionsystem 80 and the destination terminal are represented as a thirdcommunication session sed13 for call data.

Here, the resolution of an image of image data handled by the secondcommunication pattern illustrated in FIG. 4 will be described withreference to FIGS. 3 and 5. FIG. 5 is a conceptual diagram illustratingan image quality of image data transmitted and received according to theAVC standard in FIG. 4.

In the first communication session sed11 and the second communicationsession sed12 illustrated in FIG. 4, image data of three resolutionsillustrated in (a) to (c) of FIG. 3 are transmitted and received as inthe first communication session sed1 and the second communicationsession sed2 illustrated in FIG. 2. Meanwhile, in the thirdcommunication session sed13 illustrated in FIG. 4, moderate-resolutionimage data illustrated in FIG. 5 is transmitted and received.

Hardware Configuration of Embodiment

Next, a hardware configuration of the present embodiment will bedescribed. FIG. 6 is an external appearance diagram of a call terminalaccording to the present embodiment. Referring to FIG. 6, the terminal10 includes a housing 1100, an arm 1200, and a camera housing 1300. Ofthese, a front sidewall surface 1110 of the housing 1100 is providedwith an air intake surface (not illustrated) formed by a plurality ofair intake holes, and a rear sidewall surface 1120 of the housing 1100is provided with an exhaust surface 1121 formed by a plurality ofexhaust holes. Thus, as a cooling fan built in the housing 1100 isdriven, external air in the rear of the terminal 10 is introducedthrough the air intake surface (not illustrated), and air is exhaustedfrom the rear of the terminal 10 through the exhaust surface 1121. Asound pick-up hole 1131 is formed on a right sidewall surface 1130 ofthe housing 1100, and a voice, a sound, a noise, or the like are pickedup by a built-in microphone 114 which will be described later.

An operation panel 1150 is formed on the right sidewall surface 1130 ofthe housing 1100, and the operation panel 1150 is provided with aplurality of operation buttons 108 a to 108 e, a power supply switch109, and an alarm lamp 119, which will be described later, and alsoprovided with an output surface 1151 formed by a plurality of audiooutput holes through which a sound from a built-in speaker 115, whichwill be described later, is output. An accommodating unit 1160 servingas a concave portion that accommodate the arm 1200 and the camerahousing 1300 is formed on a left sidewall surface 1140 side of thehousing 1100. The right sidewall surface 1130 of the housing 1100 isprovided with a plurality of connection ports 1132 a to 1132 c used toelectrically connect a cable with a display I/F 117 which will bedescribed later. Meanwhile, the left sidewall surface 1140 of thehousing 1100 is provided with a connection port (not illustrated) usedto eclectically connect a cable 120 c for the display 120 to an externaldevice connection I/F 118 which will be described later.

In the following, an arbitrary one of the operation buttons 108 a to 108e is referred to as an “operation button 108”, and an arbitrary one ofthe connection ports 1132 a to 1132 c is referred to as a “connectionport 1132”.

Next, the arm 1200 is attached to the housing 1100 through a torquehinge 1210, and the arm 1200 is configured to be vertically rotatablewith a range of a tilt angle θ₁ of 135° with respect to the housing1100. FIG. 6 illustrates a state in which the tilt angle θ₁ is 90°. Abuilt-in camera 112 is disposed in the camera housing 1300, and canimage the user, a document, a room, or the like. The camera housing 1300is provided with a torque hinge 1310. The camera housing 1300 isattached to the arm 1200 through the torque hinge 1310. Further, thecamera housing 1300 is configured to be horizontally rotatable in arange of a pan angle of θ₂ of ±180° with respect to the arm 1200 andvertically rotatable in a range of a tilt angle θ₃ of ±45° with respectto the arm 1200 when the state illustrated in FIG. 6 is 0°.

Each of the relay device 30, the call management system 50, theconversion system 80, the program providing system 90, and themaintenance system 100 has the same external appearance as a generalserver computer, and thus a description thereof will not be made.

FIG. 7 is a hardware configuration diagram of a terminal according tothe present embodiment. As illustrated in FIG. 7, the terminal 10according to the present embodiment includes a central processing unit(CPU) 101 that controls an operation of the terminal 10 in general, aread only memory (ROM) 102 that stores a program used to drive the CPU101 such as an initial program loader (IPL), a random access memory(RAM) 103 used as a work area of the CPU 101, a flash memory 104 thatstores various kinds of data such as a program for the terminal 10,image data, and audio data, a solid state drive (SSD) 105 that controlsreading or writing of various kinds of data on the flash memory 104according to control of the CPU 101, a media drive 107 that controlsreading or writing (storing) of data on a recording medium 106 such as aflash memory, the operation button 108 operated to select a destinationof the terminal 10, the power supply switch 109 used to power on or offthe terminal 10, and a network I/F 111 used to transmit data using thecommunication network 2.

Further, the terminal 10 includes the built-in camera 112 that images asubject according to control of the CPU 101 and obtains image data, animaging element I/F 113 that controls driving of the camera 112, thebuilt-in microphone 114 that receives a sound, the built-in speaker 115that outputs a sound, an audio input output I/F 116 that processes aninput and an output of an audio signal between the microphone 114 andthe speaker 115 according to control of the CPU 101, the display I/F 117that transmits image data to the external display 120 according tocontrol of the CPU 101, the external device connection I/F 118 used toconnect various kinds of external devices, the alarm lamp 119 thatnotifies of abnormality of various kinds of functions of the terminal10, and a bus line 110 such as an address bus or a data bus used toelectrically connect the above-mentioned components as illustrated inFIG. 5.

The display 120 is a display unit configured with a liquid crystaldisplay (LCD) device or an organic EL device that displays a subjectimage, an operation icon, or the like. The display 120 is connected tothe display I/F 117 through the cable 120 c. The cable 120 c may be acable for an analog RGB (VGA) signal, a cable for a component video, ora cable for high-definition multimedia interface (HDMI) or digital videointerface (DVI).

The camera 112 includes a lens and a solid-state imaging element thatconverts light into electric charges and digitizes a subject image(video), and a complementary metal oxide semiconductor (CMOS), a chargecoupled device (CCD), or the like is used as the solid-state imagingelement.

An external device such as an external camera, an external microphone,and an external speaker may be electrically connected to the externaldevice connection I/F 118 through a universal serial bus (USB) cableinserted into the connection port 1132 of the housing 1100 illustratedin FIG. 6. When the external camera is connected, the external cameratakes priority over the built-in camera 112 and is driven according tocontrol of the CPU 101. Similarly, when the external microphone isconnected or when the external speaker is connected, the externalmicrophone or the external speaker takes priority over the built-inmicrophone 114 or the built-in speaker 115 and is driven according tocontrol of the CPU 101.

The recording medium 106 is configured to be removably attached to theterminal 10. As long as non-volatile memory that performs reading orwriting of data according to control of the CPU 101, the recordingmedium 106 is not limited to the flash memory 104 and may includeelectrically erasable and programmable ROM (EEPROM) or the like.

FIG. 8 is a hardware configuration diagram of a management systemaccording to the present embodiment of the present invention. The callmanagement system 50 includes a CPU 201 that controls an operation ofthe call management system 50 in general, a ROM 202 that stores aprogram used for driving of the CPU 201 such as an IPL, a RAM 203 usedas a work area of the CPU 201, and a hard disk (HD) 204 that storesvarious kinds of data such as a program for the call management system50, a hard disk drive (HDD) 205 that controls reading or writing ofvarious kinds of data on the HD 204 according to control of the CPU 201,a media drive 207 that controls reading or writing (storing) of data ona recording medium 206 such as a flash memory, a display 208 thatdisplays various kinds of information such as a cursor, a menu, awindow, a text, or an image, a network I/F 209 that performs datacommunication via the communication network 2, a keyboard 211 includinga plurality of keys used to input a text, a digit, various kinds ofinstructions, or the like, a mouse 212 used to select or execute variouskinds of instructions, select a processing target, or move a cursor, aCD-ROM drive 214 that controls reading or writing of various kinds ofdata on a compact disc read only memory (CD-ROM) 213 as an example of aremovable recording medium, and a bus line 210 such as an address bus ora data bus used to electrically connect the above-mentioned componentsas illustrated in FIG. 8.

Meanwhile, the relay device 30, the conversion system 80, the programproviding system 90, and the maintenance system 100 have the samehardware configuration as the call management system 50, and thus adescription thereof will not be made. However, each HD 204 storesvarious kinds of data such as a program that controls each of the relaydevice 30, the conversion system 80, the program providing system 90,and the maintenance system 100.

The programs for the terminal 10, the relay device 30, the conversionsystem 80, the program providing system 90, and the maintenance system100 may be recorded in a computer readable recording medium (therecording medium 106 or the like) as a file of an installable format oran executable form, and distributed. As another example of the recordingmedium, there are a compact disc recordable (CD-R), a digital versatiledisk (DVD), a Blu-ray disc, and the like.

Functional Configuration of Embodiment

Next, a functional configuration of the present embodiment will bedescribed. FIG. 9 is a functional block diagram of the terminal 10, therelay device 30, the call management system 50, and the conversionsystem 80 that configure a part of the call system 1 according to thepresent embodiment. Referring to FIG. 9, the terminal 10, the relaydevice 30, the call management system 50, and the conversion system 80are connected to perform data communication with one another via thecommunication network 2.

Functional Configuration of Terminal

The terminal 10 includes a transceiving unit 11, an operation inputreceiving unit 12, a login requesting unit 13, an imaging unit 14, anaudio input unit 15 a, an audio output unit 15 b, a display control unit16, a delay detecting unit 17, and a storing/reading processing unit 19.Each unit is any one of the components illustrated in FIG. 7 and is afunction or a device that is operated and implemented according to aninstruction from the CPU 101 that follows a program for the terminal 10developed from the flash memory 104 onto the RAM 103. Further, theterminal 10 includes a storage unit 1000 that is constructed by the RAM103 illustrated in FIG. 7 and the flash memory 104 illustrated in FIG.7.

Each Functional Configuration of Terminal

Next, each functional configuration of the terminal 10 will be describedin detail with reference to FIGS. 7 and 9. In the following, when eachfunctional configuration of the terminal 10 is described, a relationwith a main component for implementing each functional configuration ofthe terminal 10 among the components illustrated in FIG. 7 will be alsodescribed.

The transceiving unit 11 of the terminal 10 illustrated in FIG. 9 isimplemented by the network I/F 111 illustrated in FIG. 7 according to aninstruction from the CPU 101 illustrated in FIG. 7, and transmits orreceives various kinds of data (or information) to or from anotherterminal, device, or system via the communication network 2. Thetransceiving unit 11 starts to receive each piece of status informationrepresenting a status of each terminal serving a destination candidatethrough the call management system 50 before starting a call with adesired destination terminal. The status information represents not onlyan operation status (an online status or an offline status) of eachterminal 10 but also a detailed status representing whether eachterminal 10 is available or busy, or whether or not the user has lefthis/her seat even though each terminal 10 is online. Further, the statusinformation represents not only the operation status of each terminal 10but also various statuses such as a status representing that the cable120 c is removed from the terminal 10, a status in which a sound isoutput but an image is not output, and a status (MUTE) in which a soundis not output. The following description will proceed with an example inwhich the status information represents the operation status.

The operation input receiving unit 12 is implemented by the operationbutton 108 and the power supply switch 109 illustrated in FIG. 7according to an instruction from the CPU 101 illustrated in FIG. 7, andreceives various kinds of inputs made by the user. For example, when theuser turned on the power supply switch 109 illustrated in FIG. 7, theoperation input receiving unit 12 illustrated in FIG. 9 receives apower-on input and turns on power.

The login requesting unit 13 is implemented according to an instructionfrom the CPU 101 illustrated in FIG. 7, and automatically transmitslogin request information to request a login and a current IP address ofthe request source terminal from the transceiving unit 11 to the callmanagement system 50 via the communication network 2 when the power-oninput is received. Further, when the user turned off the power supplyswitch 109 that is in an on state, the transceiving unit 11 transmitsstatus information representing power off to the call management system50, and then the operation input receiving unit 12 completely turned offthe power. Thus, the call management system 50 side can detect that theterminal 10 has transitioned from the power-on state to the power-offstate.

The imaging unit 14 is implemented by the camera 112 and the imagingelement I/F 113 illustrated in FIG. 7 according to an instruction fromthe CPU 101 illustrated in FIG. 7, and images a subject and outputsobtained image data.

The audio input unit 15 a is implemented by the audio input output I/F116 illustrated in FIG. 7 according to an instruction from the CPU 101illustrated in FIG. 7, and converts the user's sound into an audiosignal through the microphone 114 and receives audio data related to theaudio signal. The audio output unit 15 b is implemented by the audioinput output I/F 116 illustrated in FIG. 7 according to an instructionfrom the CPU 101 illustrated in FIG. 7, and outputs an audio signalrelated to audio data to the speaker 115 and outputs a sound from thespeaker 115.

The display control unit 16 is implemented by the display I/F 117illustrated in FIG. 7 according to an instruction from the CPU 101illustrated in FIG. 7, and performs control such that received imagedata having different resolutions are combined and combined image datawill be transmitted to the display 120 as will be described later. Thedisplay control unit 16 can cause the destination list to be displayedon the display 120 by transmitting information of the list received fromthe call management system 50 to the display 120.

The delay detecting unit 17 is implemented according to an instructionfrom the CPU 101 illustrated in FIG. 7, and detects a delay time (ms) ofimage data or audio data transmitted from another terminal 10 throughthe relay device 30.

The storing/reading processing unit 19 is implemented by the SSD 105illustrated in FIG. 7 according to an instruction from the CPU 101illustrated in FIG. 7 or is implemented according to an instruction fromthe CPU 101, and performs a process of storing various kinds of data inthe storage unit 1000 or reading various kinds of data stored in thestorage unit 1000. The storage unit 1000 stores terminal identification(ID) used to identify the terminal 10, a password, and the like.Further, image data and audio data received when a call with thedestination terminal is performed are overwritten and stored in thestorage unit 1000 each time image data and audio data are received. Ofthese, an image is displayed on the display 120 based on image datawhich is not overwritten, and a sound is output from the speaker 115based on audio data that is not overwritten.

The terminal ID and a relay device ID (which will be described later) ofthe present embodiment represent identification information, such as alanguage, a text, a symbol, or a sign, which is used to uniquelyidentify the terminal 10 and the relay device 30, respectively. Theterminal ID and the relay device ID may be identification information inwhich at least two of a language, a text, a symbol, and a sign arecombined.

<Functional Configuration of Relay Device>

The relay device 30 includes a transceiving unit 31, a status detectingunit 32, a data quality verifying unit 33, a changed quality managingunit 34, a data quality changing unit 35, and a storing/readingprocessing unit 39. Each unit is any one of the components illustratedin FIG. 8 and is a function or a device that is operated and implementedaccording to an instruction from the CPU 201 that follows a program forthe relay device 30 developed from the HD 204 onto the RAM 203. Further,the relay device 30 includes a storage unit 3000 that is constructed bythe RAM 203 illustrated in FIG. 8 and the HD 204 illustrated in FIG. 8.

Changed Quality Management Table

FIG. 10 is a conceptual diagram illustrating a changed qualitymanagement table. In the storage unit 3000, a changed quality managementdatabase (DB) 3001 configured with a changed quality management tableillustrated in FIG. 10 is constructed. In the changed quality managementtable, an IP address of the terminal 10 serving as a relay destination(destination) of image data is managed in association with an imagequality of image data which is relayed to this relay destination by therelay device 30.

Each Functional Configuration of Relay Device

Next, each functional configuration of the relay device 30 will bedescribed in detail. In the following, when each functionalconfiguration of the relay device 30 is described, a relation with amain component for implementing each functional configuration of therelay device 30 among the components illustrated in FIG. 8 will be alsodescribed.

The transceiving unit 31 of the relay device 30 illustrated in FIG. 9 isimplemented by the network I/F 209 illustrated in FIG. 8 according to aninstruction from the CPU 201 illustrated in FIG. 8, and transmits orreceives various kinds of data (or information) to or from anotherterminal, device, or system via the communication network 2. Thetransceiving unit 31 performs initialization of a communication sessionin an own device.

Further, the transceiving unit 31 transmits session start instructioninformation to instruct a start of a communication session (a firstcommunication session) to a destination represented by an IP address ofthe request source terminal among IP addresses received by thetransceiving unit 31. Further, the transceiving unit 31 transmitssession start instruction information to instruct a start of acommunication session (a second communication session) and an IP addressof the destination terminal to a destination represented by an IPaddress of the conversion system 80 among IP addresses received by thetransceiving unit 31.

The status detecting unit 32 is implemented according to an instructionfrom the CPU 201 illustrated in FIG. 8, and detects the operation statusof the relay device 30 having the status detecting unit 32. As theoperation status, there are an “online” state, an “offline” state, a“busy” state, and a “temporary stop” state.

The data quality verifying unit 33 is implemented according to aninstruction from the CPU 201 illustrated in FIG. 8, and verifies animage quality of image data to be relayed by searching the changedquality management table (see FIG. 10) using the IP address of thedestination terminal as a search key and extracting an image quality ofcorresponding image data to be relayed.

The changed quality managing unit 34 is implemented according to aninstruction from the CPU 201 illustrated in FIG. 8, and changes contentof the changed quality management table (see FIG. 10) based on qualityinformation (which will be described later) transmitted from the callmanagement system 50. For example, while a video conference is beingperformed such that high-quality image data is transmitted and receivedbetween the request source terminal (the terminal 10 aa) having theterminal ID of “01aa” and the destination terminal (the terminal 10 ba)having the terminal ID of “01ba”, when the request source terminal (theterminal 10 bb) and the destination terminal (the terminal 10 ca), whichperform another video conference, start a video conference via thecommunication network 2 and thus image data is received with a delay bythe destination terminal (the terminal 10 ba), the relay device 30lowers an image quality of image data received until now from a highimage quality to a moderate image quality. In this case, content of thechanged quality management table (see FIG. 10) is changed based on thequality information represented by the moderate image quality such thatan image quality of image data to be relayed by the relay device 30 islowered from the high image quality to the moderate image quality.

The data quality changing unit 35 is implemented according to aninstruction from the CPU 201 illustrated in FIG. 8, an image quality ofimage data transmitted from a transmission source terminal is changedbased on the changed content of the changed quality management table(see FIG. 10).

The storing/reading processing unit 39 is implemented by the HDD 205illustrated in FIG. 8 according to an instruction from the CPU 201illustrated in FIG. 8, and performs a process of storing various kindsof data in the storage unit 3000 or reading various kinds of data storedin the storage unit 3000.

Functional Configuration of Management System

The call management system 50 includes a transceiving unit 51, aterminal authenticating unit 52, a status managing unit 53, anextracting unit 54, a determining unit 55, a session managing unit 56, aquality deciding unit 57, a delay time managing unit 58, and astoring/reading processing unit 59. Each unit is any one of thecomponents illustrated in FIG. 8 and is a function or a device that isoperated and implemented according to an instruction from the CPU 201that follows a program for the call management system 50 developed fromthe HD 204 onto the RAM 203. Further, the call management system 50includes a storage unit 5000 that is constructed by the HD 204illustrated in FIG. 8.

Relay Device Management Table

FIG. 11 is a conceptual diagram illustrating a relay device managementtable. In the storage unit 5000, a relay device management DB 5001configured with a relay device management table illustrated in FIG. 11is constructed. In the relay device management table, an operationstatus of each relay device 30, a reception date and time in whichstatus information represented by the operation status is received bythe call management system 50, an IP address of the relay device 30, anda maximum data call rate (Mbps) in the relay device 30 are managed inassociation with the relay device ID of each relay device 30. Forexample, the relay device management table illustrated in FIG. 11represents that the operation status of a relay device 30 a having therelay device ID of “111a” is “online”, a date and time in which thestatus information is received by the call management system 50 is“13:00, Nov. 10, 2011”, the IP address of the relay device 30 a is“1.2.1.2”, and the maximum data call rate in the relay device 30 a is100 Mbps.

Terminal Information Management Table

FIG. 12 is a conceptual diagram illustrating a terminal informationmanagement table. In the storage unit 5000, a terminal informationmanagement DB 5002 configured with a terminal information managementtable illustrated in FIG. 12 is constructed. In the terminal informationmanagement table, a password for authentication, a model number of theterminal 10, a serial number of the terminal 10, and a communicationscheme of the terminal 10 are managed in association with each terminalID of each of all terminals 10 managed by the call management system 50.For example, the terminal information management table illustrated inFIG. 12 represents that a terminal ID of a terminal 10 aa is “01aa”, apassword is “aaaa”, a model number is “9001”, a serial number is “2001”,and a communication scheme is “dedicated”.

A communication scheme represented as “dedicated” is a communicationscheme used by the dedicated terminal A illustrated in FIGS. 2 and 4. Acommunication scheme represented as “non-dedicated 1” is a communicationscheme used by the non-dedicated terminal D illustrated in FIG. 4.Further, a communication scheme represented as “non-dedicated 2” is acommunication scheme other than communication schemes which arerespectively used by the dedicated terminal A and the non-dedicatedterminal D.

Terminal Status Management Table

FIG. 13 is a conceptual diagram illustrating a terminal statusmanagement table. In the storage unit 5000, a terminal status managementDB 5003 configured with a terminal status management table illustratedin FIG. 13 is constructed. In the terminal status management table, aterminal name of each terminal 10 set as a destination, an operationstatus of each terminal 10, a reception date and time in which loginrequest information (which will be described later) is received by thecall management system 50, and an IP address of the terminal 10 aremanaged in association with the terminal ID of each terminal 10. Forexample, the terminal status management table illustrated in FIG. 13represents that a terminal name of a terminal 10 aa having the terminalID of “01aa” is “AA terminal of Tokyo business office in Japan”, theoperation status is “online (call possible state)”, a date and time inwhich login request information is received by the call managementsystem 50 is “13:40, Nov. 10, 2011”, and the IP address of the terminal10 aa is “1.2.1.3”.

However, in the terminal status management table, the IP address of theterminal 10 other than the dedicated terminal A, that is, the IP addressof the non-dedicated terminal D or the like is not a management targetand thus not managed.

Destination List Management Table

FIG. 14 is a conceptual diagram illustrating a destination listmanagement table. In the storage unit 5000, a destination listmanagement DB 5004 configured with a destination list management tableillustrated in FIG. 14 is constructed. In the destination listmanagement table, terminals ID of destination terminals that areregistered as a destination terminal candidate are managed inassociation with a terminal ID of a request source terminal thatrequests a start of a call. For example, the destination list managementtable illustrated in FIG. 14 represents that destination terminalcandidates that can request a start of a call from a request sourceterminal (a terminal 10 aa) having the terminal ID of “01aa” are aterminal 10 ab having the terminal ID of “01ab”, a terminal 10 ba havingthe terminal ID of “01ba”, and a terminal 10 bb having the terminal IDof “01bb”. As an arbitrary request source terminal requests the callmanagement system 50 to add or delete, the destination terminalcandidate is added or deleted and updated. In the terminal statusmanagement table (see FIG. 13), the IP address of the terminal 10 otherthan the dedicated terminal A is a management target, but in thedestination list management table (see FIG. 14), the terminal ID of theterminal 10 other than the dedicated terminal A is a management target.

Session Management Table

FIG. 15 is a conceptual diagram illustrating a session management table.In the storage unit 5000, a session management DB 5005 configured with asession management table illustrated in FIG. 15, is constructed. In thesession management table, the relay device ID of the relay device 30used to relay image data and audio data, the terminal ID of the requestsource terminal, the terminal ID of the destination terminal, areception delay time (ms) when image data is received in the destinationterminal, and a reception date and time in which delay time informationrepresenting the delay time is transmitted from the destination terminaland received by the call management system 50 are managed in associationwith one another. For example, the session management table illustratedin FIG. 15 represents that the relay device 30 a (the relay device ID“111a”) relays image data and audio data between the request sourceterminal (a terminal 10 aa) having the terminal ID “01aa” and thedestination terminal (a terminal 10 ca) having the terminal ID of“01ca”, and the delay time of image data at “14:00, Nov. 10, 2011” inthe destination terminal (the terminal 10 ca) is 200 (ms). Further, whena call is performed between the two terminals 10, the reception date andtime of the delay time information may be managed based on the delaytime information transmitted from the request source terminal other thanthe destination terminal. However, when a call is performed betweenthree or more terminals 10, the reception date and time of the delaytime information is managed based on the delay time informationtransmitted from the terminal 10 at the reception side of image data andaudio data.

Conversion Management Table

FIG. 16 is a conceptual diagram illustrating a conversion managementtable. In the storage unit 5000, a conversion management DB 5006configured with a conversion management table illustrated in FIG. 16 isconstructed. In the conversion management table, the terminal ID of thenon-dedicated terminal (including terminals of non-dedicated 1 andnon-dedicated 2), the IP address of the conversion system 80, and the IPaddress of the non-dedicated terminal are managed in association withone another.

Quality Management Table

FIG. 17 is a conceptual diagram illustrating a quality management table.In the storage unit 5000, a quality management DB 5007 configured with aquality management table illustrated in FIG. 17 is constructed. In thequality management table, the delay time information representing thedelay time of image data and image quality information representing animage quality of image data (a quality of an image) are managed inassociation with each other such that as the delay time (ms) of imagedata the request source terminal or the destination terminal increases,an image quality of image data to be relayed by the relay device 30decreases.

Each Functional Configuration of Management System

Next, each functional configuration of the call management system 50will be described in detail. In the following, when each functionalconfiguration of the call management system 50 is described, a relationwith a main component for implementing each functional configuration ofthe call management system 50 among the components illustrated in FIG. 8will be also described.

The transceiving unit 51 is implemented by the network I/F 209illustrated in FIG. 8 according to an instruction from the CPU 201illustrated in FIG. 8, and transmits or receives various kinds of data(or information) to or from another terminal, device, or system via thecommunication network 2.

The terminal authenticating unit 52 is implemented according to aninstruction from the CPU 201 illustrated in FIG. 8, searches theterminal information management table (see FIG. 12) using the terminalID and the password included in the login request information receivedthrough the transceiving unit 51 as the search key, and performsterminal authentication by determining whether or not the same terminalID and password are managed in the terminal information managementtable.

The status managing unit 53 is implemented according to an instructionfrom the CPU 201 illustrated in FIG. 8, and manages the terminal ID ofthe request source terminal, the operation status of the request sourceterminal, the reception date and time in which login request informationis received by the call management system 50, and the IP address of therequest source terminal to be stored in the terminal status managementtable (see FIG. 13) in association with one another in order to managethe operation status of the request source terminal that has made thelogin request. Further, when the user switches the power supply switch109 of the terminal 10 from an on state to an off state, the statusmanaging unit 53 changes the operation status of the terminal statusmanagement table (see FIG. 13) representing the online state to theoffline state based on the status information representing the power offtransmitted from the terminal 10.

The extracting unit 54 is implemented according to an instruction fromthe CPU 201 illustrated in FIG. 8, and searches each management DBconstructed in the storage unit 5000 using various kinds of search keysand extracts data (information) corresponding to the search keys as asearch result.

For example, the extracting unit 54 searches the destination listmanagement table (see FIG. 14) using the terminal ID of the requestsource terminal that has made the login request as a key, and extractsthe terminal ID of the destination terminal candidate that can perform acall with the request source terminal. Further, the extracting unit 54searches the terminal status management table (see FIG. 13) using theterminal ID of the destination terminal candidate as the search key andextracts the operation status for each terminal ID. Thus, the extractingunit 54 can acquire the operation status of the destination terminalcandidate that can perform a call with the request source terminal thathas made the login request.

Further, the extracting unit 54 searches the destination list managementtable (see FIG. 14) using the terminal ID of the request source terminalthat has made the login request as a key, and extracts the terminal IDof another request source terminal in which the terminal ID of therequest source terminal is registered as the destination terminalcandidate. Further, the extracting unit 54 searches the terminal statusmanagement table (see FIG. 13) using the terminal ID as the search key,and acquires the operation status of the request source terminal thathas made the login request.

Further, the extracting unit 54 searches the terminal status managementtable (see FIG. 13) using the terminal ID of the terminal 10 received bythe transceiving unit 51 as the search key, and extracts the IP addressof the corresponding terminal 10. Further, the extracting unit 54searches the terminal information management table (see FIG. 12) usingthe terminal ID of the terminal 10 received by the transceiving unit 51as the search key, and extracts corresponding communication schemeinformation. Further, the extracting unit 54 searches the conversionmanagement table (see FIG. 16) using the terminal ID of the terminal 10received by the transceiving unit 51 as the search key, and extracts theIP address of the corresponding conversion system 80 and the IP addressof the terminal 10 related to the received terminal ID.

Further, the extracting unit 54 searches the quality management table(see FIG. 17) using the delay time information received by thetransceiving unit 51 as the search key, and extracts image qualityinformation of corresponding image data.

Further, the extracting unit 54 searches the terminal status managementtable (see FIG. 13) using the IP address of the destination terminal asthe search key, and extracts the corresponding terminal ID.

Next, the determining unit 55 is implemented according to an instructionfrom the CPU 201 illustrated in FIG. 8, and determines whether or notthe communication scheme used by the terminal 10 is the communicationscheme used by the dedicated terminal A.

The session managing unit 56 is implemented according to an instructionfrom the CPU 201 illustrated in FIG. 8, and manages the relay device IDof the relay device 30 used to relay call data, the terminal ID of therequest source terminal, the terminal ID of the destination terminal,the reception delay time (ms) when image data is received by thedestination terminal, and a reception date and time in which the delaytime information representing the delay time is transmitted from thedestination terminal and received by the call management system 50 to bestored in the session management table (see FIG. 15) of the storage unit5000 in association with one another. Further, the session managing unit56 generates a session ID used to establish a communication session.

The quality deciding unit 57 decides an image quality of image data tobe relayed by the relay device 30 based on the image quality informationof image data extracted by the extracting unit 54.

The delay time managing unit 58 is implemented according to aninstruction from the CPU 201 illustrated in FIG. 8, and manages thedelay time represented by the delay time information to be stored in adelay time field portion of a record including a terminal ID extractedby the extracting unit 54 in the session management table of the sessionmanagement DB 5005 (see FIG. 15).

The storing/reading processing unit 59 is implemented by the HDD 205illustrated in FIG. 8 according to an instruction from the CPU 201illustrated in FIG. 8, and performs a process of storing various kindsof data in the storage unit 5000 or reading various kinds of data storedin the storage unit 5000.

Functional Configuration of Conversion System

The conversion system 80 includes a transceiving unit 81, acommunication scheme converting unit 82, and a storing/readingprocessing unit 89. Each unit is any one of the components illustratedin FIG. 8 and is a function or a device that is operated and implementedaccording to an instruction from the CPU 201 that follows a program forthe conversion system 80 developed from the HD 204 onto the RAM 203.Further, the conversion system 80 includes a storage unit 8000 that isconstructed by the RAM 203 illustrated in FIG. 8 and/or the HD 204illustrated in FIG. 8. The storage unit 8000 stores conversion rule dataused to convert communication data.

Functional Configuration of Conversion System

Next, each functional configuration of the conversion system 80 will bedescribed with reference to FIGS. 8 and 9. In the following, when eachfunctional configuration of the conversion system 80 is described, arelation with a main component for implementing each functionalconfiguration of the conversion system 80 among the componentsillustrated in FIG. 8 will be also described.

The transceiving unit 81 of the conversion system 80 illustrated in FIG.9 is implemented by the network I/F 209 illustrated in FIG. 8 accordingto an instruction from the CPU 201 illustrated in FIG. 8, and transmitsor receives various kinds of data (or information) to or from anotherterminal, device, or system via the communication network 2. Further,the transceiving unit 81 transmits session start instruction informationto instruct a start of a communication session (a third communicationsession) to a destination represented by destination informationtransmitted by the relay device 30. In addition, an IP address, auniform resource identifier (URI), or the like may be used as thedestination information.

The communication scheme converting unit 82 mutually converts acommunication scheme of call data transmitted from the request sourceterminal and communication scheme of call data transmitted from thedestination terminal based on communication scheme conversion rule datastored in the storage unit 8000.

The storing/reading processing unit 89 is implemented by the HDD 205illustrated in FIG. 8 according to an instruction from the CPU 201illustrated in FIG. 8, and performs a process of storing various kindsof data stored in the storage unit 8000 or reading various kinds of datastored in the storage unit 8000.

Process and Operation of Embodiment

Next, the first communication pattern in which a call is performedbetween the two dedicated terminals A will be described with referenceto FIGS. 18 to 25. Specifically, the description will proceed with anexample a call is performed between the terminal 10 aa serving as thededicated terminal A and the terminal 10 ca serving as the dedicatedterminal A. FIG. 18 is a sequence diagram illustrating a process of apreliminary step to start a call between terminals. In FIG. 18, variouskinds of pieces of management information are transmitted and receivedaccording to the management communication session sei illustrated inFIG. 2.

First, when the user turns on the power supply switch 109 illustrated inFIGS. 6 and 7, the operation input receiving unit 12 illustrated in FIG.9 receives the power-on input and turns on the power as illustrated inFIG. 18 (step S21). Then, when the power-on input is received, the loginrequesting unit 13 automatically transmits login request informationrepresenting a login request to the call management system 50 via thecommunication network 2 through the transceiving unit 11 (step S22). Thelogin request information includes a terminal ID used to identify an owndevice serving as the request source terminal (the terminal 10 aa) and apassword. The terminal ID and the password are data which is read fromthe storage unit 1000 through the storing/reading processing unit 19 andtransmitted to the transceiving unit 11. Further, when the login requestinformation is transmitted from the request source terminal (theterminal 10 aa) to the call management system 50, the call managementsystem 50 at the reception side can detect the IP address of the requestsource terminal (the terminal 10 aa) at the transmission side.

Next, the terminal authenticating unit 52 of the call management system50 searches the terminal information management table (see FIG. 12)using the terminal ID and the password included in the login requestinformation received through the transceiving unit 51 as the search key,and performs terminal authentication by determining whether or not thesame terminal ID and password are managed in the terminal informationmanagement DB 5002 (step S23). Since the same terminal ID and passwordare managed by the terminal authenticating unit 52, when it isdetermined that there is a login request from the terminal 10 having anappropriate right of usage, the status managing unit 53 stores theterminal ID of the request source terminal (the terminal 10 aa), theoperation status, the reception date and time in which login requestinformation is received, and the IP address of the request sourceterminal (the terminal 10 aa) in the terminal status management table(see FIG. 13) in association with one another (step S24). Thus, in theterminal status management table (see FIG. 13), the operation status“online”, the reception date and time “2011.11.10.13:40”, and the IPaddress “1.2.1.3” of the request source terminal (the terminal 10 aa)are managed in associated with one another using the terminal ID “01aa”.

Then, the transceiving unit 51 of the call management system 50transmits authentication result information representing theauthentication result obtained by the terminal authenticating unit 52 tothe request source terminal (the terminal 10 aa) that has made the loginrequest via the communication network 2 (step S25). In the presentembodiment, the description will proceed with an example in which theterminal authenticating unit 52 determines that the terminal 10 has anappropriate right of usage.

The extracting unit 54 of the call management system 50 searches thedestination list management table (see FIG. 14) using the terminal ID“01aa” of the request source terminal (the terminal 10 aa) that has madethe login request as the search key, and extracts the terminal ID of thedestination terminal candidate that can perform communication with therequest source terminal (the terminal 10 aa) (step S26). Here, theterminal IDs (“01ab”, “01ba”, . . . ) of the destination terminals (theterminals 10 ab, 10 ba, . . . ) corresponding to the terminal ID “01aa”of the request source terminal (the terminal 10 aa) are assumed to beextracted.

Next, the extracting unit 54 searches the terminal status managementtable (see FIG. 13) using the terminal IDs (“01ab”, “01ba”, . . . ) ofthe destination terminal candidate extracted in step S26 as the searchkey and acquires the operation statuses of the terminals (10 ab, 10 ba,. . . ) by reading the operation status (“offline”, “online”, . . . ) ofeach terminal ID (step S27).

Next, the transceiving unit 51 transmits destination status informationincluding the terminal IDs (“01ab”, “01ba”, . . . ) used in step S27 asthe search key and the operation status (“offline”, “online”, . . . ) ofthe corresponding destination terminals (the terminals 10 ab, 10 ba, . .. ) to the request source terminal (the terminal 10 aa) via thecommunication network 2 (step S28). Thus, the request source terminal(the terminal 10 aa) can detect the current operation statuses(“offline”, “online”, . . . ) of the terminals (10 ab, 10 ba, . . . )serving as the destination terminal candidate that can performcommunication with the request source terminal (the terminal 10 aa).

Further, the extracting unit 54 searches the destination list managementtable (see FIG. 14) using the terminal ID “01aa” of the request sourceterminal (the terminal 10 aa) that has made the login request as thesearch key, and extracts the terminal IDs of other request sourceterminals in which the terminal ID “01aa” of the request source terminal(the terminal 10 aa) is registered as the destination terminal candidate(step S29). In the destination list management table illustrated in FIG.14, “01ba”, “01ca”, and “01da” are extracted as the terminal IDs ofother request source terminal. In the following, for the sake ofsimplification of description, the description will proceed with theexample in which “01ba”, “01ca”, and “01da” are extracted as theterminal IDs of other request source terminals.

Next, the extracting unit 54 searches the terminal status managementtable (see FIG. 13) using the terminal ID “01aa” of the request sourceterminal (the terminal 10 aa) that has made the login request as thesearch key, and acquires the operation status of the request sourceterminal (the terminal 10 aa) that has made the login request (stepS30). Then, the transceiving unit 51 transmits the destination statusinformation including the terminal ID “01aa” of the request sourceterminal (the terminal 10 aa) acquired in step S30 and the operationstatus “online” to the terminals (10 ba and 10 ca) whose operationstatus is set to “online” in the terminal status management table (seeFIG. 13) among the terminals (10 ba, 10 ca, and 10 da) related to theterminal IDs (“01ba”, “01ca”, and “01da”) extracted in step S29 (stepS31-1, S31-2). Further, when the transceiving unit 51 transmits thedestination status information to the terminals (10 ba and 10 ca), theIP address of the terminal managed in the terminal status managementtable (see FIG. 13) is referred to on the basis of each of the terminalIDs (“01ba” and “01ca”). Thus, the terminal ID “01aa” of the requestsource terminal (the terminal 10 aa) that has made the login request andthe operation status “online” can be transmitted to each of the otherdestination terminals (the terminals 10 ba and 10 ca) that can performcommunication with the request source terminal (the terminal 10 aa) thathas made the login request as the destination.

The operation status of the terminal 10 da serving as the non-dedicatedterminal D is not managed in the terminal status management table (seeFIG. 13), and thus the terminal ID “01aa” of the request source terminal(the terminal 10 aa) that has made the login request and the operationstatus “online” are hardly transmitted to the terminal 10 da. In otherwords, the non-dedicated terminal D side hardly use a service ofacquiring the operation status of the dedicated terminal A.

Meanwhile, even in another terminal 10, when the user turns on the powersupply switch 109 illustrated in FIGS. 6 and 7 similarly to step S21,the operation input receiving unit 12 illustrated in FIG. 9 receives thepower-on input, and the same process as the process of steps S22 toS31-1, S31-2 is performed, and thus a description thereof will not bemade.

Next, the description will proceed with an example in which a call isperformed between the two dedicated terminals A with reference to FIGS.6 and 9 and FIGS. 19 to 22. FIG. 19 is a sequence diagram illustrating acall start request.

Referring to FIG. 19, first, when the user of the request sourceterminal (the terminal 10 aa) serving as the dedicated terminal A pushesdown the operation button 108 illustrated in FIG. 6 and selects thedestination terminal (the terminal 10 ca) serving as the dedicatedterminal A that is the destination candidate, the operation inputreceiving unit 12 illustrated in FIG. 9 receives a request to start acall with the destination terminal (the terminal 10 ca) (step S41).Then, the transceiving unit 11 of the request source terminal (theterminal 10 aa) transmits start request information representing a callstart desire to the call management system 50 (step S42). The startrequest information includes the terminal ID “01aa” of the requestsource terminal (the terminal 10 aa) and the terminal ID “01ca” of thedestination terminal (the terminal 10 ca).

Then, the status managing unit 53 of the call management system 50illustrated in FIG. 9 changes all the operation status field portions ofthe records respectively including the terminal ID “01aa” and theterminal ID “01ca” in the terminal status management table (see FIG. 13)to “online (busy)” based on the terminal ID “01aa” of the request sourceterminal (the terminal 10 aa) and the terminal ID “01ca” of thedestination terminal (the terminal 10 ca) included in the start requestinformation (step S43). In this state, the request source terminal (theterminal 10 aa) and the destination terminal (the terminal 10 ca) do notstart a call but becomes the busy state, and when another terminal 10desires to make a call to the request source terminal (the terminal 10aa) or the destination terminal (the terminal 10 ca), an alert tone or adisplay representing a so-called busy state is output.

Next, the session managing unit 56 of the call management system 50generates a session ID used to establish a communication session (stepS44). Then, the call management system 50 determines a communicationscheme that can be used by the destination terminal (the terminal 10 ca)(step S45).

Here, step S45 will be described in detail with reference to FIG. 20.FIG. 20 is a flowchart illustrating a determination of a communicationscheme.

Referring to FIG. 20, the extracting unit 54 searches the terminalinformation management table (see FIG. 12) based on the terminal ID“01ca” of the destination terminal (the terminal 10 ca) received by thetransceiving unit 51, and extracts a corresponding communication schemeinformation (step S45-1).

Next, the determining unit 55 determines whether or not a communicationscheme represented by the extracted communication scheme information isa communication scheme that can be used by the request source terminal(the terminal 10 aa) serving as the dedicated terminal A (step S45-2).Specifically, the determining unit 55 determines whether or not acommunication scheme represented by the communication scheme informationextracted by the extracting unit 54 is the same as a communicationscheme that can be used by the request source terminal (the terminal 10aa). The two communication schemes are determined to be the same as eachother when the two communication schemes are the same in both of thecall control scheme and the coding scheme, but the two communicationschemes are determined to be not the same as each other when the twocommunication schemes are different in at least one of the call controlscheme and the coding scheme.

Then, when the determining unit 55 determines that the two communicationschemes are the same as each other (YES in step S45-2), the processproceeds to step S61 illustrated in FIG. 21 which will be describedlater. Here, since the destination terminal (the terminal 10 ca) is thesame dedicated terminal A as the request source terminal (the terminal10 aa), the description will proceed starting from step S61. FIG. 21 isa sequence diagram illustrating a process of establishing acommunication session before a call is performed between the twodedicated terminals A. In the present embodiment, the description willproceed with an example in which the relay device 30 a connected to thesame LAN 2 a as in the request source terminal (the terminal 10 aa) isused among a plurality of relay devices 30.

Referring to FIG. 21, the call management system 50 transmits sessioninitialization request information to initialize a communication sessionestablished by the relay device 30 a to the relay device 30 a throughthe transceiving unit 51 (step S61). The session initialization requestinformation includes the session ID generated in step S44 and the IPaddresses of the request source terminal (the terminal 10 aa) and thedestination terminal (the terminal 10 ca) managed by the terminal statusmanagement table (see FIG. 13). The call management system 50 alsotransmits the IP address of the call management system 50 whentransmitting the session initialization request information to the relaydevice 30 a. Thus, the transceiving unit 31 of the relay device 30 areceives the session initialization request information and the IPaddress of the call management system 50.

Next, the transceiving unit 31 of the relay device 30 a initializes thecommunication session (step S62). Then, the transceiving unit 31transmits the session start instruction information to instruct a startof the communication session to the request source terminal (theterminal 10 aa) (step S63). The session start instruction informationincludes the session ID transmitted from the call management system 50.Further, the relay device 30 a also transmits the IP address of therelay device 30 a to the request source terminal (the terminal 10 aa)when transmitting the session start instruction information. Thus, thetransceiving unit 11 of the request source terminal (the terminal 10 aa)receives the session start instruction information and the IP address ofthe relay device 30 a.

Similarly, the transceiving unit 31 transmits the session startinstruction information to instruct a start of the communication sessionto the destination terminal (the terminal 10 ca) (step S64). The sessionstart instruction information includes the session ID transmitted fromthe call management system 50. Further, the relay device 30 a alsotransmits the IP address of the relay device 30 a to the destinationterminal (the terminal 10 ca) when transmitting the session startinstruction information. Thus, the transceiving unit 11 of thedestination terminal (the terminal 10 ca) receives the session startinstruction information and the IP address of the relay device 30 a.

As a result, the communication session (the first communication sessionsed1 illustrated in FIG. 2) to transmit and receive call data isestablished between the request source terminal (the terminal 10 aa) andthe relay device 30 a based on step S63 (step S65-1). Further, thecommunication session (the second communication session sed2 illustratedin FIG. 2) to transmit and receive call data is established between therelay device 30 a and the destination terminal (the terminal 10 ca)based on step S64 (step S65-2).

Next, a process of transmitting and receiving call data in order toperform a call such as a video conference between the request sourceterminal and the destination terminal will be described with referenceto FIG. 22. FIG. 22 is a sequence diagram illustrating a process oftransmitting and receiving call data between the two dedicated terminalsA. In a process of transmitting a call data from the terminal 10 aa tothe terminal 10 ca in one direction and a process of transmitting calldata from the terminal 10 ca to the terminal 10 aa in a reversedirection, transmission and reception of call data, detection of thedelay time which will be described later, or the like is performed bythe same process, and thus the description will proceed withcommunication in one direction, and a description of communication inthe reverse direction will not be made.

First, the request source terminal (the terminal 10 aa) transmitssubject image data imaged by the imaging unit 14 and audio data of asound input through the audio input unit 15 a to the relay device 30 avia the communication network 2 through the transceiving unit 11 usingthe communication session sed1 (step S81). In the present embodiment,high-quality image data having the three resolutions, that is, the lowresolution, the moderate resolution, and the high resolution illustratedin FIG. 3 and audio data are transmitted. Thus, the relay device 30 areceives the image data having the three resolutions and the audio datathrough the transceiving unit 31. Then, the data quality verifying unit33 verifies a quality of an image of image data to be relayed bysearching the changed quality management table (see FIG. 10) using theIP address “1.3.1.3” of the destination terminal (the terminal 10 ca) asthe search key and extracting an image quality of corresponding imagedata to be relayed (step S82). In the present embodiment, since theverified image quality of image data is the “high image quality” and isthe same as the image quality of the image data received by thetransceiving unit 31, the relay device 30 a transfers the image datawith the same image quality and the audio data with the same audioquality to the destination terminal (the terminal 10 ca) using thecommunication session sed2 (step S83). Thus, the destination terminal(the terminal 10 ca) receives the high-quality image data having thethree resolutions, that is, the low resolution, the moderate resolution,the high resolution and the audio data through the transceiving unit 11.Then, the display control unit 16 can cause an image to be displayed onthe display 120 based on a combination of the image data having thethree image qualities, and the audio output unit 15 b can output a soundbased on the audio data.

Next, the delay detecting unit 17 of the destination terminal (theterminal 10 ca) detects the reception delay time of the image datareceived through the transceiving unit 11 at predetermined timeintervals (for example, each second (step S84). In the presentembodiment, the following description will proceed with an example inwhich the delay time is 200 (ms).

The transceiving unit 11 of the destination terminal (the terminal 10ca) transmits the delay time information representing the delay time“200 (ms)” to the call management system 50 via the communicationnetwork 2 through the management communication session sei illustratedin FIG. 2 (step S85). Thus, the call management system 50 can detect thedelay time and detect the IP address “1.3.1.3” of the terminal 10 caserving as the transmission source of the delay time information.

Next, the delay time managing unit 58 of the call management system 50searches the terminal status management table (see FIG. 13) using the IPaddress “1.3.1.3” of the destination terminal (the terminal 10 ca) asthe search key and extracts the corresponding terminal ID “01ca”, andmanages the delay time “200 (ms)” represented by the delay timeinformation to be stored in the delay time field portion in the recordof the terminal ID “01ca” in the session management table (see FIG. 15)(step S86).

Next, the quality deciding unit 57 decides the image quality as the“moderate image quality” by searching the quality management table (seeFIG. 17) using the delay time “200 (ms)” as the search key andextracting an image quality “moderate image quality” of correspondingimage data (step S87).

Next, the transceiving unit 51 searches the relay device managementtable (see FIG. 11) using the relay device ID “111a” associated with theterminal ID “01ca” in the session management table (see FIG. 15) as thesearch key, and extracts the IP address “1.2.1.2” of the correspondingrelay device 30 a (step S88). Then, the transceiving unit 51 transmitsthe quality information representing the image quality “moderate imagequality” of the image data decided in step S87 to the relay device 30 avia the communication network 2 through the management communicationsession sei (step S89). The quality information includes the IP address“1.3.1.3” of the destination terminal (the terminal 10 ca) used as thesearch key in step S86. Thus, in the relay device 30 a, the changedquality managing unit 34 manages the IP address “1.3.1.3” of thetransmission destination terminal 10 (here, the terminal 10 ca) and theimage quality “moderate image quality” of the image data to be relayedto be stored in the changed quality management table (see FIG. 10) inassociation with each other (step S90).

Next, similarly to step S81, the request source terminal (the terminal10 aa) transmits the high-quality image data having the threeresolutions, that is, the low resolution, the moderate resolution, thehigh resolution and the audio data to the relay device 30 a through thefirst communication session sed1 (step S91). Thus, in the relay device30 a, similarly to step S82, the data quality verifying unit 33 verifiesa quality of an image of image data to be relayed by searching thechanged quality management table (see FIG. 10) using the IP address“1.3.1.3” of the destination terminal (the terminal 10 ca) as the searchkey and extracting an image quality “moderate image quality” ofcorresponding image data to be relayed (step S92). In the presentembodiment, since the verified image quality of image data is the“moderate image quality” and is lower than the image quality “high imagequality” of the image data received by the transceiving unit 31, thedata quality changing unit 35 suppresses an image quality of image datafrom the “high image quality” to the “moderate image quality” andchanges the quality of the image of the image data (step S93).

Then, the transceiving unit 31 transmits the image data in which animage quality of image data has been changed to the “moderate imagequality” and the audio data in which a sound quality of a sound has notbeen changed to the destination terminal (the terminal 10 ca) via thecommunication network 2 through the second communication session sed2(step S94). Thus, the destination terminal (the terminal 10 ca) receivesimage data of a moderate image quality having two resolutions, that is,the low resolution, the moderate resolution and the audio data throughthe transceiving unit 11. Then, the display control unit 16 can cause animage to be displayed on a display 120 ca based on a combination of theimage data having the two resolutions, and the audio output unit 15 bcan output a sound based on the audio data.

As described above, when a reception delay occurs in the destinationterminal (the terminal 10 ca) that receives image data, the relay device30 a changes a quality of an image, and thus that the user who attends acall such as a video conference does not feel uncomfortable. In otherwords, a service to cope with a reception delay of image data can beprovided between the two dedicated terminals A.

Next, the second communication pattern in which a call is performedbetween the dedicated terminal A (an example of a first communicationterminal) and the non-dedicated terminal D (and example of a secondcommunication terminal) will be described with reference to FIG. 20 andFIGS. 23 to 25. Specifically, a call is performed between the terminal10 aa serving as the dedicated terminal A and the terminal 10 da servingas the non-dedicated terminal D. Further, the present embodiment will bedescribed in connection with an example in which as a communicationscheme used by the terminal 10 aa, a call control scheme is a protocolof an instant messenger (or a protocol extended from a protocol of aninstant messenger), and a coding scheme is the SVC, whereas as acommunication scheme used by the terminal 10 da, a call control schemeis the SIP, and a coding scheme is the AVC.

Further, in FIGS. 18 and 19, the second communication pattern isdifferent from the first communication pattern in that the destinationterminal (the terminal 10 da) selects the destination in step S41 ratherthan the destination terminal (the terminal 10 ca), and thus theterminal ID of the destination terminal used for transmission andreception or a search is also changed, and thus a description thereofwill not be made. Then, the description will proceed from when thedetermining unit 55 determines that the two communication schemes arenot the same in step S45-2 illustrated in FIG. 20 (NO).

In the case of the second communication pattern, the extracting unit 54searches the conversion management table (see FIG. 16) based on theterminal ID “01da” of the destination terminal (the terminal 10 da)received through the transceiving unit 51, and extracts thecorresponding IP address “1.3.2.2” of the conversion system 80 and theIP address “1.3.2.3” of the destination terminal (the terminal 10 da)(step S45-3). Then, the process proceeds to step S101 illustrated inFIG. 23 which will be described later.

FIG. 23 is a sequence diagram illustrating a process of establishing acommunication session before a call is performed between the dedicatedterminal A and the non-dedicated terminal D. Referring to FIG. 23, thecall management system 50 transmits session initialization requestinformation to initialize a communication session established by therelay device 30 a to the relay device 30 a through the transceiving unit51 (step S101). The session initialization request information includesthe session ID and the IP addresses of the request source terminal (theterminal 10 aa), the conversion system 80, and the destination terminal(the terminal 10 da). Of these, the session ID is the ID generated instep S44. The IP address of the request source terminal (the terminal 10aa) is managed in the terminal status management table (see FIG. 13).Further, the IP addresses of the conversion system 80 and thedestination terminal (the terminal 10 da) are the IP addresses extractedin step S45-3.

The call management system 50 also transmits the IP address of the callmanagement system 50 when transmitting the session initializationrequest information to the relay device 30 a. Thus, the transceivingunit 31 of the relay device 30 a receives the session initializationrequest information and the IP address of the call management system 50.

Next, the transceiving unit 31 of the relay device 30 a initializes thecommunication session (step S102). Then, the transceiving unit 31transmits the session start instruction information to instruct a startof the communication session to the request source terminal (theterminal 10 aa) (step S103). The session start instruction informationincludes the session ID transmitted from the call management system 50.Further, the relay device 30 a also transmits the IP address of therelay device 30 a to the request source terminal (the terminal 10 aa)when transmitting the session start instruction information. Thus, thetransceiving unit 11 of the request source terminal (the terminal 10 aa)receives the session start instruction information and the IP address ofthe relay device 30 a.

Similarly, the transceiving unit 31 transmits the session startinstruction information to instruct a start of the communication sessionto the conversion system 80 (step S104). The session start instructioninformation includes the session ID transmitted from the call managementsystem 50 and the IP address of the destination terminal (the terminal10 da). In other words, the transceiving unit 31 transmits the sessionstart instruction information and transmits the IP address of thedestination terminal (the terminal 10 da). Further, the relay device 30a also transmits the IP address of the relay device 30 a to theconversion system 80 when transmitting the session start instructioninformation. Thus, the transceiving unit 81 of the conversion system 80receives the session start instruction information and the IP address ofthe relay device 30 a.

Further, in the second communication pattern, the transceiving unit 81of the conversion system 80 transmits the session start instructioninformation to instruct a start of the communication session to thedestination terminal (the terminal 10 da) (step S105). The session startinstruction information includes the session ID transmitted from thecall management system 50. Further, the conversion system 80 alsotransmits the IP address of the conversion system 80 to the destinationterminal (the terminal 10 da) when transmitting the session startinstruction information. Thus, the transceiving unit 11 of thedestination terminal (the terminal 10 da) receives the session startinstruction information and the IP address of the conversion system 80.

As a result, the communication session (the first communication sessionsed11 illustrated in FIG. 4) to transmit and receive call data isestablished between the request source terminal (the terminal 10 aa) andthe relay device 30 a based on step S103 (step S106-1). Further, thecommunication session (the second communication session sed12illustrated in FIG. 4) to transmit and receive call data is establishedbetween the relay device 30 a and the conversion system 80 based on stepS104 (step S106-2). Further, the communication session (the thirdcommunication session sed13 illustrated in FIG. 4) to transmit andreceive call data is established between the conversion system 80 andthe destination terminal (the terminal 10 da) based on step S105 (stepS106-3).

Next, a process of transmitting and receiving call data in order toperform a call such as a video conference between the request sourceterminal and the destination terminal will be described with referenceto FIG. 24. FIG. 24 is a sequence diagram illustrating a process oftransmitting and receiving call data between the dedicated terminal Aand the non-dedicated terminal D.

First, the request source terminal (the terminal 10 aa) transmitssubject image data imaged by the imaging unit 14 and audio data of asound input through the audio input unit 15 a to the relay device 30 avia the communication network 2 through the transceiving unit 11 usingthe communication session sed11 (step S121). In the second communicationpattern, similarly to the first communication pattern, high-qualityimage data having the three resolutions, that is, the low resolution,the moderate resolution, and the high resolution illustrated in FIG. 3and audio data are transmitted. Thus, the relay device 30 a receives theimage data having the three resolutions and the audio data through thetransceiving unit 31.

Next, the relay device 30 a transmits the high-quality image data havingthe three resolutions and the audio data to the conversion system 80 viathe communication network 2 through the transceiving unit 31 using thecommunication session sed12 (step S122). Thus, the conversion system 80receives the image data having the three resolutions and the audio datathrough the transceiving unit 81.

Next, the communication scheme converting unit 82 of the conversionsystem 80 converts the communication scheme of the image data having thethree resolutions from the communication scheme used by the requestsource terminal (the terminal 10 aa) to the communication scheme used bythe destination terminal (the terminal 10 da) based on the conversionrule data stored in the storage unit 8000 in advance (step S123). Here,as the conversion of the communication scheme is performed, the imagedata having the three resolutions (the high resolution, the moderateresolution, and the low resolution) illustrated FIG. 3 is converted intothe image data having one resolution (the moderate resolution)illustrated in FIG. 5.

Next, the conversion system 80 transmits the audio data and themoderate-resolution image data to the terminal 10 da via thecommunication network 2 through the transceiving unit 81 using thecommunication session sed13 (step S124). Thus, the destination terminal(the terminal 10 da) receives the audio data and the moderate-resolutionimage data through the transceiving unit 11.

Meanwhile, when image data and audio data are transmitted from thedestination terminal (the terminal 10 da) to the request source terminal(the terminal 10 aa), the destination terminal (the terminal 10 da)transmits the audio data and the moderate-resolution image data to theconversion system 80 via the communication network 2 through thetransceiving unit 11 using the communication session sed13 asillustrated in FIG. 24 (step S125). Thus, the conversion system 80receives the audio data and the moderate-resolution image data throughthe transceiving unit 81.

Next, the communication scheme converting unit 82 of the conversionsystem 80 converts the communication scheme of the audio data and themoderate-resolution image data from the communication scheme used by thedestination terminal (the terminal 10 da) to the communication schemeused by the request source terminal (the terminal 10 aa) based on theconversion rule data stored in the storage unit 8000 in advance (stepS126).

FIG. 25 is a conceptual diagram illustrating an image quality of imagedata converted by the conversion system. As the communication scheme isconverted in step S126, the image data having one resolution (themoderate resolution) illustrated in FIG. 5 is converted intolow-resolution image data illustrated in (a) of FIG. 25,moderate-resolution image data illustrated in (c) of FIG. 25, and imagedata with a low moderate resolution which is a moderate resolutionbetween the moderate resolution and the low resolution as illustrated in(b) of FIG. 25. In other words, even when moderate-resolution image datais transmitted from the destination terminal (the terminal 10 da)serving as the non-dedicated terminal D, the conversion system 80 doesnot convert the moderate-resolution image data into the high-resolutionimage data transmitted in step S122, and the moderate-resolution imagedata transmitted from the destination terminal (the terminal 10 da) hasthe maximum resolution and is converted into image data having the threeresolutions, that is, the moderate resolution, the moderate resolutionbetween the moderate resolution and the low resolution, and the lowresolution.

Next, the conversion system 80 transmits the audio data and the imagedata having the three resolutions to the relay device 30 a via thecommunication network 2 through the transceiving unit 81 using thecommunication session sed12 (step S127). Thus, the relay device 30 areceives the audio data and the image data having the three resolutionsthrough the transceiving unit 31. Then, the relay device 30 a transmitsthe audio data and the image data having the three resolutions to therequest source terminal (the terminal 10 aa) via the communicationnetwork 2 through the transceiving unit 31 using the communicationsession sed11 (step S128). Thus, the request source terminal (theterminal 10 aa) receives the audio data and the image data having thethree resolutions through the transceiving unit 11.

Main Effects of Present Embodiment

As described above, according to the present embodiment, the sessioninitialization request information to be transmitted from the callmanagement system 50 to the relay device 30 a includes the IP addressesof the request source terminal, the conversion system 80, and thedestination terminal. Thus, the relay device 30 a can transmit thesession start instruction information to the IP address of the requestsource terminal and transmit the session start instruction informationincluding the IP address of the destination terminal to the IP addressof the conversion system 80. As a result, the conversion system 80 cantransmit the session start instruction information to the IP address ofthe destination terminal.

As the session initialization request information is transmitted by thecall management system 50 as described above, the first communicationsession sed11 can be established between the relay device 30 and therequest source terminal, the second communication session sed12 can beestablished between the relay device 30 and the conversion system 80,and the third communication session sed13 can be established between theconversion system 80 and the destination terminal. Thus, even when therequest source terminal and the destination terminal use different callschemes from each other, the communication schemes of call data aremutually converted by the conversion system 80, and there is an effectby which a call can be implemented.

Supplement of Embodiment

The above description has been made in connection with the example inwhich the request source terminal or the dedicated terminal A is used asan example of the first communication terminal, and the destinationterminal or the non-dedicated terminal D is used as an example of thesecond communication terminal. However, the present invention is notlimited to this example, and the destination terminal or thenon-dedicated terminal D may be used as an example of the firstcommunication terminal, and the request source terminal or the dedicatedterminal A may be used as an example of the second communicationterminal.

The call data is an example of communication data. The communicationdata includes a text or image file data. The terminal 10 is an exampleof the communication terminal. For example, an information processingterminal that transmits and receives the file data as well as a terminalthat performs a call may be used as the communication terminal. Further,the call management system 50 is an example of the communicationmanagement system. For example, a file management system that managesprocessing of the file data as well as a system that manages a call maybe used as the communication management system. In addition, the callsystem 1 is an example of the communication system. The communicationsystem is constructed by the communication terminal and thecommunication management system.

In the above embodiment, the call management system 50 managescommunication scheme information through the terminal informationmanagement table (see FIG. 12). However, the present invention is notlimited to this example, and the request source terminal may managecommunication scheme information of the destination terminal.

As a result, in step S42 illustrated in FIG. 19, the request sourceterminal (the terminal 10 aa) can transmit the start request informationincluding the terminal ID of the request source terminal and theterminal ID of the destination terminal and the communication schemeinformation to the call management system 50. In this case, in step S41of FIG. 19, the display control unit 16 may cause a selection screenused to select the non-dedicated terminal as the destination of a callto be displayed on the display 120 and encourages the user to make aselection.

Then, when the destination is selected on the selection screen, in stepS42 of FIG. 19, the request source terminal (the terminal 10 aa)transmits the start request information including information(communication scheme information) representing that the destinationterminal ID is the non-dedicated terminal to the call management system.In this case, the call management system 50 needs not execute step S45-1of FIG. 20, determines that the communication scheme of the destinationterminal is not “dedicated” based on the communication schemeinformation included in the start request information (NO in step S45-2of FIG. 20), and causes the process to proceed to step S45-3 of FIG. 20.

In addition, the user needs not necessarily make a selection on theselection screen. For example, when the user already knows thedestination information of the destination terminal, the operation inputreceiving unit 12 may receive an input of the destination information(the IP address or the like) of the destination terminal from the user.In this case, in step S42, the request source terminal transmits thestart request information including the destination information of thedestination terminal and the information (the communication schemeinformation) representing that the destination terminal is“non-dedicated” rather than the terminal ID of the destination terminalto the call management system 50. Then, at the call management system 50side, in step S45-2, the determining unit 55 determines that thedestination terminal represented by the destination information is not“dedicated”, and then causes the process to proceed to step S45-3.Further, in step S45-3, the extracting unit 54 extracts the destinationinformation of the conversion system 80 based on the destinationinformation of the non-dedicated terminal, and causes the process toproceed to step S101.

Further, the terminal ID may be stored in the terminal 10 in advance atthe time of factory shipment or may be input by the user.

In the above-described embodiment, the relay device 30, the callmanagement system 50, the conversion system 80, the program providingsystem 90, and the maintenance system 100 may be constructed by a singlecomputer or may be constructed by a plurality of computers in whichrespective portions (functions or devices) are divided and arbitrarilyallocated. When the program providing system 90 is constructed by asingle computer, a program transmitted by the program providing system90 may be divided into a plurality of modules and then transmitted ormay be transmitted without any division. Further, when the programproviding system 90 is constructed by a plurality of computers,transmission from each computer may be performed in a state in which theprogram is divided into a plurality of modules.

In the present embodiment, as an example in which call control schemesof terminals are different from each other, a protocol of an instantmessenger (or a protocol extended from a protocol of an instantmessenger) and the SIP have been described, but the present invention isnot limited to this combination as long as call control schemes ofterminals are different from each other. For example, a combination of aprotocol of an instant messenger (or a protocol extended from a protocolof an instant messenger) and H.323 may be used. Further, a combinationof a protocol of an instant messenger and a protocol extended from aprotocol of an instant messenger may be used.

Further, all a recording medium such as a CD-ROM storing each program ofthe above-described embodiment, the HD 204 storing the program, and theprogram providing system 90 including the HD 204 may be provided insideor outside the country as a program product.

Further, in the above-described embodiment, a quality of an image ismanaged by the changed quality management table illustrated in FIG. 10and the quality management table illustrated in FIG. 17, focusing on theresolution of an image of image data as an example of a quality of animage of image data to be relayed by the relay device 30, and thepresent invention is not limited to this example. As another example ofa quality, a quality may be managed focusing on the depth of an imagequality of image data, a sampling frequency in a sound of audio data, ora bit length in a sound of audio data. Further, the audio data may bedivided into three kinds of resolutions (the high resolution, themoderate resolution, and the low resolution) and then transmitted andreceived.

In FIGS. 11, 13, and 15, the reception date and time is managed, but thepresent invention is not limited to this example, and it is preferablethat at least a reception time of the reception date and time bemanaged.

Further, in the above-described embodiment, the IP address of the relaydevice 30 is managed in FIG. 11, and the IP address of the terminal 10is managed in FIG. 13, but the present invention is not limited to thisexample. When destination information specifies the relay device 30 onthe communication network 2 or destination information specifies theterminal 10 on the communication network 2, each fully qualified domainname (FQDN) may be managed. In this case, an IP address corresponding tothe FQDN is acquired by a known domain name system (DNS) server.

Further, in the above-described embodiment, the video conference systemhas been described as an example of the call system 1, but the presentinvention is not limited to this example, and the call system 1 may be atelephone system such as an internet protocol (IP) telephone or anInternet telephone. Further, the call system 1 may be a car navigationsystem. In this case, for example, one terminal 10 corresponds to a carnavigation device mounted in a vehicle, and the other terminal 10corresponds to a management terminal or a management server of amanagement center that manages a car navigation device, or a carnavigation device mounted in another device. Further, the call system 1may be a communication system of a mobile telephone. In this case, forexample, the terminal 10 corresponds to a mobile phone.

In addition, in the above-described embodiment, image data and audiodata have been described as an example of the call data, but the calldata is not limited to this example, call data may be haptic (touch)data. In this case, sensory information generated by the user's touch atone terminal side is transmitted to the other terminal side. Further,the call data may be smell data. In this case, smelling (bad smelling)at one terminal is transmitted to the other terminal side. Furthermore,the call data is preferably at least one of image data, audio data,haptic data, and smell data.

In addition, the above-described embodiment has been described inconnection with the example in which a video conference is performed bythe call system 1, but the present invention is not limited to thisexample, and the call system 1 may be used for a meeting, an ordinaryconversation between family members or friends, or provision ofinformation in one direction.

Although the invention has been described with respect to specificembodiments for a complete and clear disclosure, the appended claims arenot to be thus limited but are to be construed as embodying allmodifications and alternative constructions that may occur to oneskilled in the art that fairly fall within the basic teaching herein setforth.

1. A communication management system for managing first and secondcommunication terminals that transmit and receive predeterminedcommunication data, the communication management system comprising: astorage unit configured to store therein destination informationrepresenting a destination of the first communication terminal thatestablishes a first communication session with a relay device thatrelays the communication data, destination information representing adestination of a conversion system that performs mutual conversionbetween a communication scheme of communication data transmitted fromthe first communication terminal and a communication scheme ofcommunication data transmitted from the second communication terminaland establishes a second communication session with the relay device,and destination information representing a destination of the secondcommunication terminal that establishes a third communication sessionwith the conversion system; a receiving unit configured to receive startrequest information to start communication between the firstcommunication terminal and the second communication terminal from thefirst communication terminal; an extracting unit configured to extractdestination information of each of the first and the secondcommunication terminals and the conversion system stored in the storageunit, on the basis of the received start request information; and atransmitting unit configured to transmit the extracted destinationinformation to the relay device.